Re: How to centalize the container in a page?

Are there any parent containers above your root container in that code? If so, you'll need to make sure that every container level uses horizontalAlignment: HorizontalAlignment.Fill as a container can only ever be as big as its parent.

If not, the quick and dirty method would be add preferredHeight: 1280 to your root container. This should be ok for the Q10 as it'll automatically set your container's height to be 720, the maximum space available.